1. Technical Field
The present invention relates generally to secure authentication of objects, and more particularly to the use of an electronic circuit for the secure authentication of an object.
2. Description of the Related Art
In a data network, it is desirable to authenticate the identity of objects such as access cards or data terminals in order to prevent electronic theft of money, services, and information, and to prevent tampering with the configuration and operating characteristics of the network. Authentication of the identity of an object is sometimes the only means of electronically identifying the user of the object. For example, for billing purposes, a portable telephone may automatically transmit a user's authentication code. Unfortunately, it is possible for a thief to intercept the user's authentication code, and create a “clone” of the user's portable phone. Calls made on the clone phone are then charged to the legitimate user's account. For critical applications, such as access to cash from an automatic teller machine, the user is often required to supply a password in addition to presenting an electronically readable object such as a credit or debit card containing an authentication code. The password offers some additional protection, but the password can often be intercepted when the user manually enters the password into a data terminal. Although user passwords can offer a high level of security if they are changed frequently, it is burdensome for a user to change frequently his or her password. What is desired is a mechanism that would ensure the unique identity of an electronic object used for authentication. Therefore, the only burden that need be placed on the user is to be in possession of the electronic object whenever the electronic object is used for authentication.